Tiarella plant named ‘Susquehanna’

ABSTRACT

A new and distinct  Tiarella cordifolia  plant characterized by its deep green foliage with deep purple markings and white blooms.

Botanical classification: Tiarella cordifolia.

Varietal denomination: ‘Susquehanna’.

SUMMARY OF THE INVENTION

The new Tiarella cordifolia as selected during 2007 as a seedling from the garden at the Nursery of Sinclair A. Adam Jr. at Coatesville, Pa., U.S.A. The exact parentage of the new variety is unknown. It resulted from seedlings grown from open-pollinated plants of Tiarella cordifolia, and Tiarella cordifolia var. collina. Several hundred plants are grown for seed production, and some or all of these plants are likely included in the parentage of the new variety of the present invention.

The new variety has been carefully preserved and studied since the time of its discovery. Had such new variety not been discovered and preserved, it would have been lost to mankind.

It was found that the new Tiarella cordifolia, variety of the present invention exhibits the following combination of characteristics: (a) exhibits a compact mounding clump growth habit with substantial runners, (b) forms attractive white flowers on branched flower stalks, (c) forms lobed ovate green leaves having a matte finish during the summer that bear maroon markings primarily along the leaf veins maroon and this pigment expands in the late summer outward from along the veins. In fall the leaves turn darker red of variable intensity during the fall, but retain a green margin. and (d) is particularly well suited for growing as a distinctive ornamental ground cover, creating a dense stand in a season.

The new variety of the present invention can be readily distinguished from other previously known varieties of the species in view of the distinctive combination of characteristics discussed herein. The red, and green spring, summer, and fall color is considered to be particularly noteworthy.

The new variety well meets the needs of the horticultural industry and expands the choices of ornamental ground covers which fills in as a stand well. It performs well wherever a ground cover is desired, and is particularly well suited for use as a border planting, use in shaded areas, and for ecology and restoration casting open pollinated seedlings, and asexual runners.

The runners (stolons) and flower stems of clumps have been used to asexually propagate the new variety at Delhi, N.Y. (laboratory), and Coatesville, (breeder and nursery) Pa., U.S.A. It has been found that the distinctive combination of characteristics of the new variety is firmly fixed and is reliably transmitted to succeeding generations. During observations to date, the new variety has been found to be readily amenable to such propagation.

The new variety ‘Susquehanna’ can be compared to ‘Elizabeth Oliver’ (not patented), which differs from ‘Susquehanna’ in having foliage that turns purple rather than red with green margins in fall. ‘Susquehanna’ can also be compared to cultivars from the same breeding program, ‘Delaware’ (U.S. patent application Ser. No. 12/589,997), ‘Octoraro’ (U.S. patent application Ser. No. 12/589,995), and ‘Lehigh’ (U.S. patent application Ser. No. 12/589,998). ‘Delaware’ differs from ‘Susquehanna’ in having foliage that is less lobed. ‘Octoraro’ differs from ‘Susquehanna’ in having more pubescent foliage that is yellow in color in fall and in having flowers that are tinted pink in color. ‘Lehigh’ differs from ‘Susquehanna’ in having foliage that is less pubescent with more pointed lobes and in having more maroon markings between the veins.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts a two year-old plant of ‘Susquehanna’ as grown in a garden in Baltimore, Md. in May. The plant parts depicted in FIG. 2, FIG. 3, and FIG. 4 were taken from a two year-old plant of ‘Susquehanna’ as grown in a garden in Coatsville, Pa. in May.

FIG. 1: Shows a typical plant in bloom.

FIG. 2: Shows the maturation of inflorescences with the least mature on the left and the most mature on the right.

FIG. 3: Shows leaves in various stages of development.

FIG. 4: Shows a stolon.

DETAILED DESCRIPTION

The following is a detailed description of the new variety that was obtained while observing plants being grown outdoors, and in the greenhouse during 2007-2008 at Coatesville, Pa., U.S.A. The plants were approximately two years of age and were being grown on their own roots. The chart used in the identification of color is The R.H.S. Colour Chart of The Royal Horticultural Society, London, England. More common color terms are to be accorded their ordinary dictionary significance.

-   Botanical classification: Tiarella cordifolia ‘Susquehanna’. -   Plant:     -   -   Habit.—Compact mounding clump, several runners.         -   Type.—Evergreen.         -   Height.—Approximately 15 to 20 cm without blooms, and             approximately 25 to 30 cm with blooms.         -   Width.—Approximately 30 cm.         -   Stolons.—Greyed-Green Group 195A in color, surface is             pubescent with hairs 0.5 to 2 mm in length, internode length             1.25 to 2 cm. -   Foliage:     -   -   Type.—Simple.         -   Shape.—Ovate to broadly ovate, palmately five-lobed             (seven-lobed as the leaf expands) with an elongated central             lobe, and irregularly crenate margins on all lobes having             mucronate teeth. Each tooth has a small point, which is             relatively firm with a leaf vein extending to the end of the             tip.         -   Length.—Approximately 9.5 to 12.1 cm.         -   Width.—Approximately 8-11 cm.         -   Margins.—Incised with dentation.         -   Apex.—The lobes are broadly obtuse to rounded and cuspidate.         -   Base.—Cordate.         -   Texture.—Upper surface; Slightly rugose with a velvet matte             finish with hairs about 2 mm in length and 2 to 3 mm apart             with greater density on margins, lower surface; glabrous             with hairs along the veins.         -   Arrangement.—Basal clump, with branched runners 4-8 in             number, usually 20 to 38 cm in length.         -   Venation.—Palmately reticulate. -   Young foliage: On the upper surface Yellow-Green Group 144A to 144B,     and Greyed-Purple Group 187A at the center and along the main vein,     and on the lower surface Yellow-Green Group 146B to 146C. -   Adult foliage: On the upper surface Green Group 137B to 137D, and     Brown Group 200B at the center and along the main vein, and on the     lower surface Yellow-Green Group 146B to Greyed-Green Group 191A. -   Fall foliage: Both the ventral leaf surface (upper) and the dorsal     leaf surface (lower) are characterized by areas of light red and     darker reddish-purple that are near and through the following     colors: Red Group 49D and Red-Purple Group 62D in the lighter areas     to Red Group 53D and Greyed-Purple Group 186B in the mid-tones to     Greyed-Purple Group 187A and 187B in the darker areas. The dorsal     leaf surface exhibits a slightly glossier appearance when compared     to the more matte appearance of the ventral leaf surface that     commonly is increased in expression in the autumn foliage.     -   -   Petiole.—The length commonly varies from approximately 9 to             15 cm, and the diameter commonly is approximately 2 to 3 mm,             Yellow-Green Group N144D in color, surface is pubescent with             hairs 0.5 mm to 2 mm in length. -   Inflorescence:     -   -   Type.—Raceme and perfect (bisexual).         -   Number.—Approximately 30 to 50 blooms per raceme.         -   Bearing.—On a branched stalk commonly having a height of             approximately 25 to 30 cm, with up to 2-3 short side             branches. Side branches are 2-10 cm in length, bearing 5-10             blooms.         -   Lastingness of inflorescence.—About 3 weeks.         -   Flower buds.—Ellipsoid in shape, perigynous, 2 to 3 mm in             depth and 2 mm in diameter, White Group 155B in color.         -   Calyx.—Five-lobed, White Group 155B in color, 6 to 8 mm in             diameter.         -   Petals.—Five.         -   Petal shape.—Triangular.         -   Stamens.—Ten, 3 to 4 mm in length. Anthers Orange Group 27             D.         -   Pistil.—One, 4 mm in length.         -   Flower size.—Approximately 6 to 9 mm on average per floret.         -   Color.—On the dorsal surface White Group 155B and on the             ventral surface White Group 155A.         -   Fragrance.—Slight and sweet.         -   Pedicel.—Approximately 6 to 7 mm in length on average,             Yellow-Green Group 146D in color. -   Development:     -   -   Vegetation.—Clump-forming, with runners (stolons).         -   Blooming.—Abundantly when initially blooms during May/June             and sporadically thereafter during the summer and fall.         -   Resistance to disease.—No susceptibility to diseases has             been noted during observations to date.         -   Hardiness.—Has proven to grow well in U.S.D.A. Hardiness             Zones No. 4 to 7.         -   Propensity to form fruit/seeds.—Approx 0.16 grams per (1             year old) plant (about 500 seeds).

Plants of the new ‘Susquehanna’ variety have not been observed under all possible environmental conditions to date. Accordingly, it is possible that the phenotype expression may vary somewhat with changes in light intensity and duration, cultural practices, and other environmental conditions. 

1. A new and distinct Tiarella plant as herein illustrated and described. 